A conventional umbrella of this type as disclosed, for example, in U.S. Pat. No. 3,850,188 has a rib assembly as shown in FIGS. 1 through 4. The umbrella with such rib assembly is capable of being closed in an extended state without collapsing the rib structure for putting the umbrella against an umbrella stand or resting it against a wall etc. when the umbrella is temporarily closed in a standby state for further use and capable of being collapsed into a compact form convenient for storage and handy for carrying when it is not in use. This conventional umbrella, however, has some difficulty in collapsing operation from its extended closed position to its collapsed closed position.
In FIGS. 1 through 4, showing a conventional umbrella of this type with an automatic opening means, numeral 1 designates a known contractile or telescopic center rod and numeral 2 a ferrule which is fixedly secured to the center rod 1 directly adjacent the upper end thereof. A runner 5 is slidably mounted on said center rod 1 intermediate the ends thereof. A main rib 3 is pivotally connected at its upper end to said ferrule 2 and at its lower end to the inner end of an auxiliary link 8. The outer end of said auxiliary link 8 is connected to the intermediate portion of an end rib 6. Said end rib 6 is spaced from said main rib 3 and connected thereto at its intermediate portion through a connecting link 7. A strut 4 is pivotally connected at its inner end to the runner 5 and at its outer end to the pivotal joint of the auxiliary link 8 and the end rib 6. The strut 4 may alternatively be pivotally connected at its outer end to the auxiliary link 8, the connecting link 7 or the end rib 6, or the pivotal joint of the end rib 6 and the connecting link 7.
Numeral 9 designates an actuator slidably mounted on the center rod 1 under the runner 5. A compression spring 10 rests at its upper end against said runner 5 and at its lower end against said actuator 9. An actuator strut 11 is pivotally connected at its lower end to the actuator 9 and at its upper end to the strut 4 intermediate the ends thereof. Numeral 12 designates a lock means having a detent 12a to lock the automatic opening means and 13 a means for receiving the tip end of the end rib 6.
In the thus constructed structure, when the actuator 9 is lowered by hand from the opened position as shown in FIG. 1, the umbrella is closed into an uncollapsed position as shown in FIG. 2. When the umbrella is further required to be collapsed into a position, as shown in FIG. 4, the operation for moving the rib assembly from the uncollapsed closed position to the collapsed closed position undergoes some difficulty as mentioned above.
Stated illustratively, in the uncollapsed or extended closed position, the strut 4 undergoes a force acting to expand the strut 4 by the action of the compression spring 10 so that when the lock means 12 is operated to release the locking of the actuator 9, the automatic opening means is immediately actuated only to release the rib assembly to its original opened position, as shown in FIG. 1, failing to move the rib assembly into the intended collapsed closed position, as shown in FIG. 4. Accordingly, in order to move the rib assembly from the uncollapsed closed position of FIG. 2 to the collapsed closed position of FIG. 4, the operation must be done while grasping the main ribs 3, which are arranged around the center rod 1, by hand to press them inwardly, or holding or gripping the struts, which are also arranged around the center rod 1, to kill the expanding force of the automatic opening means in the position of FIG. 2. At this time, the rib assembly may be comparatively easily contracted by applying a force A in the arrow direction and a force B in the arrow direction. In this case, however, in the course of the movement of the rib assembly to the collapsed closed position of FIG. 4, the rib assembly has to assume a position as shown in FIG. 3 where not only the end rib 6 is forcibly bent but also the pivotal joints a, b, c and d undergo excessive loads possibly to result in breakage. Furthermore, the main rib 3 is violently pressed against the center rod 1 and sometimes possibly projected to the other side of the center rod 1 beyond the center line thereof, preventing the normal operation of the rib assembly.
It is therefore an object of the present invention to provide a folding umbrella of the type as mentioned above and provided with means for varying the distance in a straight line between the ends of the auxiliary link to eliminate the difficulty in operation for collapsing the rib assembly from the uncollapsed closed position to the collapsed closed position.